More particularly, the invention relates to pumps comprising:
a pump body having a sidewall extending axially between a first end which includes an inlet orifice and an open second end provided with an external collar; PA1 a piston that slides axially in said side wall, and a return spring that urges the piston towards the second end of the pump body; and PA1 a ferrule fixed in the second end of the side wall of the pump body to limit piston motion towards said second end. PA1 the pump includes a pump body extending axially between a first end that includes an inlet orifice and an open second end provided with an outside collar, the pump further including a piston that slides axially inside said pump body, and a return spring that urges the piston towards the open second end of the pump body, and the pump includes a ferrule constituted by a single piece fixed in said second end of the pump body to limit motion of the piston towards said second end; PA1 the stopper includes an axial internal passage passing therethrough, said passage including a substantially cylindrical first length towards the outside of the receptacle and a narrower second length towards the inside of the receptacle, said first and second lengths defining a shoulder facing towards the outside of the receptacle, said first length having an inside diameter that is substantially equal to the outside diameter of the collar on the pump body; PA1 the ferrule includes a flange which extends radially outwards; PA1 the pump body passes through the second length of the internal passage of the stopper, and the collar is disposed inside said first length of the internal passage of the stopper in abutment against the shoulder of the stopper; and PA1 wherein said flange of the ferrule has an outside diameter close to the outside diameter of said collar of the pump body and slightly greater than the inside diameter of the first length, and said flange is engaged as a force-fit inside said first length of the internal passage of the stopper to hold the pump in said stopper, preventing the pump body from moving towards the outside of the receptacle, both the ferrule and the stopper being made of plastics material, and the ferrule being made of a material that is harder than the stopper so that said radial flange bites into said stopper. Advantageously, said radial flange has at least one external catch with a sliding chamfered surface closer to the shoulder of the stopper and a stop surface further away from the shoulder of the stopper, so that said catch enables the flange to be put into place in the first length of the internal passage of the stopper and prevents said flange escaping from said first length of the internal passage of the stopper.
There are several well known ways of fixing such a pump on the neck of a receptacle for said fluid substance to be dispensed or sprayed, or on a stopper suitable for being fixed on such a neck. Firstly, it is possible to crimp the pump on the neck of the receptacle by means of a metal cup. That method of assembly has the drawback of being relatively unattractive, and in addition a portion of the pump body necessarily projects above the neck of the receptacle, thereby tending slightly to increase the overall size of the device for dispensing the fluid substance.
It is also possible to use a part generally referred to as a "turret" which is secured to the ferrule of the pump body. Such a turret generally has a substantially cylindrical side wall that surrounds the pump body in the vicinity of the second end, said side wall of the turret being extended radially outwards by a tab that can be fixed to the neck of a receptacle by being clamped between a screw stopper and said neck of the receptacle. That assembly method suffers from the drawback that a substantial fraction of the pump body projects above the neck of the receptacle, thereby increasing the size of the device.
In addition, it is possible to use a screw stopper that includes a through axial inside passage, said passage including a substantially cylindrical first length towards the outside of the receptacle and a narrower second length towards the inside of the receptacle, said first and second lengths defining a shoulder facing towards the outside of the receptacle, the pump body being engaged in said second length and said collar being placed in abutment against the shoulder of the stopper, and said shoulder of the pump body being held in said second length of the stopper passage by an annular locking ring that is a force-fit inside the cylindrical lateral wall of the stopper. In that assembly, it is generally necessary to interpose a flat sealing gasket between the collar of the pump body and the locking ring. That method of fixing is advantageous insofar as the pump body projects a little above the neck of the tank. However it requires the use of a locking ring and of an additional sealing gasket.